The present invention relates to a method of manufacturing an article with an electronic circuit which is composed of a circuit unit, such as a circuit board with electronic components mounted thereon, covered with a cylindrical or a sheet-like film. The invention also relates to an article with an electronic circuit manufactured by the method of manufacturing the same.
In recent years, as a method of forming circuit boards, there has been known a reflow process using a solder paste or a conductive adhesive as a bonding agent.
However, the solder paste contains zinc, which is not desirable in terms of conservation of the global environment.
The conductive adhesive contains a large amount of metallic powder filled into resin, which causes poor bond strength and low impact resistance compared to a metallic solder. To improve impact resistance, there is a separately-conducted method in which components are sealed on a board using a sealant. This method, however, brings about difficulty in later board repair, including replacement of components, and causes difficulty in recovery and recycle of the components. In addition, there are other issues, such as hardening of sealing resin that takes a long time.
In the case where the board is sealed with silicon resin or urethane resin for the purpose of protecting the board from moisture or dust, there arises difficulty, like in the above case, in later board repair including replacement of components, as well as difficulty in recovery and recycle of the components. In addition, there are other issues, such as hardening of sealing resin that takes a long time.
Japanese Laid-Open Patent Publication No. 8-18275 proposes a technology as a solution for these issues. According to this publication, a board is inserted into a rectangle bag which has a conductive layer and a thermal weld layer and whose three sides are closed. After the board is inserted through the remaining one open side of the bag, the open side is closed through heat shielding and thermal deposition for achieving electromagnetic shielding of the board.
With the above-disclosed structure, three sides of a film xe2x80x9cbagxe2x80x9d are closed in advance before the board is inserted therein, which limits the size of a board to be inserted into the bag. Accordingly, use of different sized boards requires steps of preparing different sized bags and selecting an appropriate sized bag corresponding to a board in use, making the technology complex and less general.
In order to solve the above-stated issues, the object of the present invention is to provide an article with an electronic circuit, as well as to provide a method of manufacturing the same. Each of the methods is capable of corresponding to different sized boards and is rich in generality, allows packaging for a short period of time, provides an increase in impact resistance, and facilitates recovery and recycle of components, boards, and the like.
In order to accomplish the above object, the present invention has the following embodiments.
According to a first aspect of the present invention, there is provided an electronic circuit-formed article manufacturing method characterized by manufacturing an article with an electronic circuit. A circuit board having electronic components is inserted into a cylindrical film so that the board is covered with the cylindrical film. Thereafter, both opening portions of the cylindrical film are sealed to package the circuit board.
According to a second aspect of the present invention, there is provided an electronic circuit-formed article manufacturing method including covering an area, which has electronic components on an article with an electronic circuit formed having the electronic components, with sheet-like films.
According to a third aspect of the present invention, there is provided an electronic circuit-formed article manufacturing method including covering both front and back surfaces of a circuit board having electronic components with two sheet-like films, and packaging the circuit board with the sheet-like films.
According to a fourth aspect of the present invention, there is provided a method of manufacturing an article with an electronic circuit as defined in the third aspect, wherein the front surface of the circuit board is covered with one of the two sheet-like films. The back surface of the circuit board is then covered with the other sheet-like film to package the circuit board.
According to a fifth aspect of the present invention, there is provided a method of manufacturing an article with an electronic circuit as defined in the third aspect, wherein the circuit board is packaged by simultaneously covering both the front and the back surfaces of the circuit board with the two sheet-like films.
According to a sixth aspect of the present invention, there is provided a method of manufacturing an article with an electronic circuit as defined in any one of the first to fifth aspects, wherein the film is heated in advance to be softened, and then the board is covered.
According to a seventh aspect of the present invention, there is provided a method of manufacturing an article with an electronic circuit as defined in any one of the first to sixth aspects, wherein the thickness of the film is 10 to 200 xcexcm.
According to an eighth aspect of the present invention, there is provided a method of manufacturing an article with an electronic circuit as defined in any one of the first to seventh aspects, wherein during the process of covering the board with the film, decompression is conducted between the film and the board so as to make the film follow the components or the board.
According to a ninth aspect of the present invention, there is provided a method of manufacturing an article with an electronic circuit as defined in any one of the first to eighth aspects, wherein the film is composed of a heat-shrinkable material. The film is heated and heat-shrunken so as to make the film follow the board and the components.
According to a 10th aspect of the present invention, there is provided a method of manufacturing an article with an electronic circuit as defined in any one of the first to ninth aspects, wherein the film is composed of a visible material.
According to an 11th aspect of the present invention, there is provided a method of manufacturing an article with an electronic circuit as defined in any one of the first to 10th aspects, wherein during covering of the board with the film, decompression is conducted between the film and the board through use of a hole of the component so as to make the film follow the components or the board. A valve provided in the hole then prevents gas from entering between the film and the board from outside through the air hole.
According to a 12th aspect of the present invention, there is provided a method of manufacturing an article with an electronic circuit as defined in any one of the first to 11th aspects, wherein an elastic sheet is provided between the film and the components or the board.
According to a 13th aspect of the present invention, there is provided a method of manufacturing an article with an electronic circuit as defined in any one of the first to 12th aspects, wherein an adhesion layer is provided in an internal surface of the film for adhering the film to the electronic components or the board.
According to a 14th aspect of the present invention, there is provided a method of manufacturing an article with an electronic circuit as defined in any one of the first to 13th aspects, wherein the film allows gas generated from flame retarders or solder flux used in the board and the components as well as moisture generated from the board made of paper phenol to pass from inside to outside but to prevent moisture and dust from invading the inside of the film from the outside.
According to a 15th aspect of the present invention, there is provided a method of manufacturing an article with an electronic circuit as defined in any one of the first to 14th aspects, wherein an absorbent material such as desiccants and activated carbon is provided inside the film for absorbing gas generated from flame retarders or solder flux used in the board and the components as well as moisture generated from the board made of paper phenol.
According to a 16th aspect of the present invention, there is provided a method of manufacturing an article with an electronic circuit as defined in any one of the first to 15th aspects, wherein the board is heated in advance to a temperature equal to or higher than a temperature at which the film is softened, and to a temperature lower than a temperature at which the film is melted, and to a temperature in a range so that a bonding agent to bond the board and the components is not melted. Then, the board is packaged with the film, so that the film is softened upon contact with the heated board, making the film follow the board.
According to a 17th aspect of the present invention, there is provided a method of manufacturing an article with an electronic circuit as defined in any one of the first to eighth aspects and 10th to 16th aspects, wherein the film is composed of a thermoplastic material. When the board is covered with the film, decompression is executed between the film and the board so as to make the film follow the components or the board, while at the same time, the film is heated and attached to each other to achieve sealing.
According to an 18th aspect of the present invention, there is provided a method of manufacturing an article with an electronic circuit including inserting a circuit board having electronic components into a cylindrical film. Both opening portions of the cylindrical film are then sealed, and the cylindrical film is cut to package the circuit board.
According to a 19th aspect of the present invention, there is provided a method of manufacturing an article with an electronic circuit, including printing or applying an electronic component mounting bonding agent on electrodes of a circuit board, and bringing electronic components close to above positions through mechanical application of pressure. The components are then fixed on the board through heating, and the board is packaged with cylindrical film or sheet-like films.
According to a 20th aspect of the present invention, there is provided a method of manufacturing an article with an electronic circuit as defined in the 19th aspect, wherein the electronic component mounting bonding agent is a metallic solder or a thermosetting conductive adhesive.
According to a 21st aspect of the present invention, there is provided an article with an electronic circuit, manufactured by the method of manufacturing an article with an electronic circuit formed as defined in any one of the first to 20th aspects.